* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
* @link http://status.net/
*/
-class NoticeStream
+abstract class NoticeStream
{
- const CACHE_WINDOW = 200;
-
- public $generator = null;
- public $args = null;
- public $cachekey = null;
-
- function __construct($generator, $args, $cachekey)
- {
- $this->generator = $generator;
- $this->args = $args;
- $this->cachekey = $cachekey;
- }
+ abstract function getNoticeIds($offset, $limit, $sinceId, $maxId);
function getNotices($offset=0, $limit=20, $sinceId=0, $maxId=0)
{
return $notices;
}
- function getNoticeIds($offset=0, $limit=20, $sinceId=0, $maxId=0)
- {
- $cache = Cache::instance();
-
- // We cache self::CACHE_WINDOW elements at the tip of the stream.
- // If the cache won't be hit, just generate directly.
-
- if (empty($cache) ||
- $sinceId != 0 || $maxId != 0 ||
- is_null($limit) ||
- ($offset + $limit) > self::CACHE_WINDOW) {
- return $this->generate($offset, $limit, $sinceId, $maxId);
- }
-
- // Check the cache to see if we have the stream.
-
- $idkey = Cache::key($this->cachekey);
-
- $idstr = $cache->get($idkey);
-
- if ($idstr !== false) {
- // Cache hit! Woohoo!
- $window = explode(',', $idstr);
- $ids = array_slice($window, $offset, $limit);
- return $ids;
- }
-
- // Check the cache to see if we have a "last-known-good" version.
- // The actual cache gets blown away when new notices are added, but
- // the "last" value holds a lot of info. We might need to only generate
- // a few at the "tip", which can bound our queries and save lots
- // of time.
-
- $laststr = $cache->get($idkey.';last');
-
- if ($laststr !== false) {
- $window = explode(',', $laststr);
- $last_id = $window[0];
- $new_ids = $this->generate(0, self::CACHE_WINDOW, $last_id, 0);
-
- $new_window = array_merge($new_ids, $window);
-
- $new_windowstr = implode(',', $new_window);
-
- $result = $cache->set($idkey, $new_windowstr);
- $result = $cache->set($idkey . ';last', $new_windowstr);
-
- $ids = array_slice($new_window, $offset, $limit);
-
- return $ids;
- }
-
- // No cache hits :( Generate directly and stick the results
- // into the cache. Note we generate the full cache window.
-
- $window = $this->generate(0, self::CACHE_WINDOW, 0, 0);
-
- $windowstr = implode(',', $window);
-
- $result = $cache->set($idkey, $windowstr);
- $result = $cache->set($idkey . ';last', $windowstr);
-
- // Return just the slice that was requested
-
- $ids = array_slice($window, $offset, $limit);
-
- return $ids;
- }
-
static function getStreamByIds($ids)
{
$cache = Cache::instance();
return new ArrayWrapper($wrapped);
}
}
-
- function generate($offset, $limit, $sinceId, $maxId)
- {
- $args = array_merge($this->args, array($offset,
- $limit,
- $sinceId,
- $maxId));
-
- return call_user_func_array($this->generator, $args);
- }
}